For maximum biological durability, both Service Classes and Use Classes must be considered when specifying engineered wood panels. See APA’ s guide here.
Use Classes covering plywood and OSB have replaced ‘hazard classes’. They will also cover LVL when the LVL standards have completed their update. Use Classes are based on different environmental exposures that can make the panel susceptible to deterioration. The in Eurocode 5 assign strength values and calculate deformation in load-bearing situations. They are determined by the moisture content of the panel corresponding to the environmental humidity and temperature during service.
